<template>
  <div class="home-page">

  <div class="banner">
    <div class="container">
      <h1 class="logo-font">conduit</h1>
      <p>A place to share your knowledge.</p>
    </div>
  </div>

  <div class="container page">
    <div class="row">

      <div class="col-md-9">
        <div class="feed-toggle">
          <ul class="nav nav-pills outline-active">
            <li class="nav-item" v-if="user">
              <nuxt-link 
                class="nav-link disabled"
                :class="{active: tab === 'your_feed'}"
                exact
                :to="{
                  name: 'home',
                  query: {
                    tab: 'your_feed'
                  }
                }">Your Feed</nuxt-link>
            </li>
            <li class="nav-item">
              <nuxt-link 
                class="nav-link disabled"
                :class="{active: tab === 'global_feed'}"
                exact
                :to="{
                  name: 'home',
                  query: {
                    tab: 'global_feed'
                  }
                }">Global Feed</nuxt-link>
            </li>
            <li class="nav-item" v-if="tag">
              <nuxt-link 
                class="nav-link disabled"
                :class="{active: tab === 'tag'}"
                exact
                :to="{
                  name: 'home',
                  query: {
                    tab: 'tag',
                    tag: tag
                  }
                }"># {{ tag }}</nuxt-link>
            </li>
          </ul>
        </div>

        <div class="article-preview" v-for="article in articles" :key="article.slug">
          <div class="article-meta">
            <nuxt-link :to="{
              name: 'profile', 
              params: {
                username: article.author.username
                }
              }">
              <img :src="article.author.image" />
            </nuxt-link>
            <div class="info">
              <nuxt-link class="author" :to="{
                name: 'profile', 
                params: {
                  username: article.author.username
                  }
                }">
              {{ article.author.username }}
              </nuxt-link>
              <span class="date">{{ article.createdAt | date }}</span>
            </div>
            <button class="btn btn-outline-primary btn-sm pull-xs-right" 
              :class="{active: article.favorited}" 
              @click="onFavorite(article)"
              :disabled="article.favoriteDisable">
              <i class="ion-heart"></i> {{ article.favoritesCount }}
            </button>
          </div>
          <nuxt-link class="preview-link" :to="{
            name: 'article', 
            params: {
              slug: article.slug
              }
            }">
            <h1>{{ article.title }}</h1>
            <p>{{ article.description }}</p>
            <span>Read more...</span>
            <ul class="tag-list" v-if="tag">
              <li class="tag-default tag-pill tag-outline" v-for="(item, index) in article.tagList" :key="item + index">
                {{ item }}
              </li>
            </ul>
          </nuxt-link>
        </div>

        <!-- 分页 -->
        <nav>
          <ul class="pagination">
            <li class="page-item" 
              :class="{active: item === page}"
              v-for="item in totalPage" 
              :key="item">
              <nuxt-link class="page-link" 
                :to="{
                  name: 'home',
                  query: {
                    page: item,
                    tag: $route.query.tag,
                    tab: tab
                  }
                }">
                {{ item }}
              </nuxt-link>
            </li>
          </ul>
        </nav>

      </div>

      <div class="col-md-3">
        <div class="sidebar">
          <p>Popular Tags</p>

          <div class="tag-list">
            <nuxt-link 
              :to="{
                name: 'home',
                query: {
                  tab: 'tag',
                  tag: item
                }
              }" 
              class="tag-pill tag-default" 
              v-for="item in tags" 
              :key="item">
              {{ item }}
              </nuxt-link>
          </div>
        </div>
      </div>

    </div>
  </div>

</div>
</template>

<script>
import { 
  getArticles, 
  getYourFeedArticles, 
  addFavorite,
  deleteFavorite
  } 
from '@/api/articles.js'
import { getTags } from '@/api/tag.js'
import { mapState } from 'vuex'

export default {
  name: 'HomeIndex',
  async asyncData ({ query }) {
    const page = Number.parseInt(query.page || 1)
    const limit = 10
    const tab = query.tab || 'global_feed'
    const tag = query.tag
    const loadArticles = tab === 'global_feed' || tab === 'tag' ? getArticles : getYourFeedArticles
    const [ articleRes, tagRes ] = await Promise.all([
      // 获取公共文章列表
      loadArticles({
        limit,
        offset: (page - 1) * limit,
        tag
      }),
      // 获取标签列表
      getTags()
    ])
    const { articles, articlesCount } = articleRes.data
    const { tags } = tagRes.data
    articles.forEach(item => {
      item.favoriteDisable = false
    });
    return {
      articles,  // 文章列表
      articlesCount, // 文章总数
      tags, // 标签列表
      limit, // 每页大小
      page, // 页码
      tab, // 选项卡
      tag // 数据标签
    }
  },
  watchQuery: ['page', 'tag', 'tab'],
  computed: {
    ...mapState(['user']),
    totalPage() {
      return Math.ceil(this.articlesCount / this.limit)
    }
  },
  data() {
    return {
    };
  },
  watch:{
  },
  methods: {
    async onFavorite(article) {
      console.log(article)
      article.favoriteDisable = true
      if (article.favorited) {
        // 取消点赞
        await deleteFavorite(article.slug)
        article.favorited = false
        article.favoritesCount += -1
      } else {
        // 点赞
        await addFavorite(article.slug)
        article.favorited = true
        article.favoritesCount += 1
      }
      article.favoriteDisable = false
    }
  },
};
</script>

<style scoped>

</style>